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Sylvain Adnet

University lecturer Team Paleontology
Emailsylvain.adnet@univ-montp2.fr
Phone +33 (0)4 67 14 46 52
Localization Bâtiment 22, RDC
Mots clés Elasmobranchs Evolution Fossil Record Paleobiodiversity

Education and Employment History

Since 09/2007: Lecturer, University of Montpellier 2.
2006-2007: Postdoctoral position, University of Evora  (Portugal).
2005-2006: Postdoctoral position (Lecturer – Research Associate), University of Clermont-Fd (France).
2004-2005: Postdoctoral position (Lecturer- Research Associate), University of Montpellier 2 (France).
2001-2004: Tutor (University of Noumea), Teacher and NTIC developer, New Caledonia.
2000: Ph.D. Integrative Biology, University of Montpellier 2 (France)
1997-2000: Associate junior lecturer in Paleontology, University of Montpellier 2.
1995-1996: M.Sc., Palaeontology, Phylogeny, Paleobiology (Montpellier).
1992-1994: MA, Biology/Geology (University of Poitiers). B.Sc., Biology/Geology (Poitiers, Tours).

Teaching

Licence (Biology of Organisms, Earth and Life Sciences): Principles of Palaeontology, Life History, Vertebrate and Invertebrate Palaeontology, Evolution of Paleoenvironments. Sedimentary Geology and Biostratigraphy.

Master Formation for teachers, co-manager of teaching for Master BGAE – PPP (Palaeontology, Phylogeny and Palaeobiology, see www.mbgae.org/). Principles of palaeontology and paleobiology, Paleoichthyology, Paleoenvironmental proxies and paleoecology. Systematics and Phylogeny of Fishes

 Research

My research is mainly focused on the radiation of modern Shark and Rays and particularly on the Neoselachians (Post Triassic Sharks and Rays). This large group contains more than 1000 living species to date, it is widespread in all the marine and fresh waters, and it gathers a large spectrum of predators (from plankton feeder to marine mammal hunter). Among them, a large part (40%) frequents the open and deep-water seas and remains clearly understudied (historical biology, adaptations, evolutionary history), explaining why I am focused on them (PhD thesis).  My second major point of interest concerns the Cenozoic setup of modern communities after the K/T crisis and around the multiple Palaeogene climate shifting.

Origin and evolution of the deep-sea sharks and rays

My research topics include the phylogenetic study of Recent and fossil deep sea sharks; and the review and/or the reassessment of their Meso-Cenoizoic evidences. The principal aim of these works is to provide new fossil data in a phylogenetic framework by studing their early representatives.  I studied in particular the Squalea (e.g. brumble shark, dogfish, lantern sharks, sleeper sharks, pigmy shark, etc…) and Hexanchids (cowsharks) but not only. During the two last decades, morphological and molecular analyses have proposed numerous contradictory high-level phylogenies for living sharks and rays, in congruence or not with the fossil record and the evolutionary vision of Paleoichthyologists. I try to conduct the generalized use of combined fossil and recent data or morphometric analyses in order to improve or test the different phylogenies and taxonomy assumptions. The successful result of such work is to propose several evolutionary scenarios concerning the radiation of some deep-sea sharks and rays.

Palaeogene renewal of modern selachian fauna

The purposes are to understand how the post K/T radiation took place in Atlantic and Tethys (fossils from Pacific remaining extremely rare) and why the Palaeogene sharks and rays are so different from those that frequented the post-Palaeogene Atlantic and mediterranean sea.

The palaeogene shark and ray communities inhabiting the Atlantic and Tethys were deeply different than the neogene and recent ones; a point of view highlighted by many abruptly disappearance and/or shift of groups at the end of Palaeogene. This last renewal in shark and rays communities is unclear but coincides with important change in the realm seas (closure of the eastern Tethys, opening of several IndoPacific-Atlantic seaways, end of the warm period). Large decrease of shark and rays biodiversity in Atlantic and western Tethys (Proto-Mediterranean) (e.g. disappearance of carpet sharks, bullhead sharks) is correlated with arrival of some modern forms (e.g. Requiem sharks) from Indo-Pacific. If the last area is considered as the source of origination and diversification for the marine diversity by ecologists (hot spots of diversity), this exchange during the Cenozoic period leads to consider a more complex scenario explaining the current distribution and diversity of living fish fauna.

Current Fieldwork

My fieldwork is therefore focused on improving the fossil record of deepwater forms and understanding setup of modern communities in Atlantic and Mediterranean Sea. It is being conducted in several worldwide localities around the previous areas by quarrying and collecting fossil vertebrates: especially in Palaeogene deposits of SW France (deep-sea deposits), Meso-Cenozoic deposits of Southwestern Europe (France, Portugal, Spain) and Cretaceous and Palaeogene deposits of North Africa (Morocco, Algeria, Tunisia, Libya) and Middle East (Egypt, Pakistan, Iran). These sites yielded important fossils, documenting the diversity and origins of numerous groups of neoselachians, particularly those adapted to the deepwater. Other fieldwork projects are being in use in collaboration with different fieldwork teams working in Brazil, Peru, Myanmar, Lithuania and Angola for instance.

Some publications

Adnet, S., Cappetta, H. Elnahas, S., Strougo, A. (2011) A new Priabonian Chondrichthyans assemblage from the Western Desert, Egypt. Correlation with the Fayum oasis. Journal of African Earth Sciences 61:27-37

Adnet, S. et al. (2010): A new Eocene vertebrate fauna (Selachians and Mammals) from southwestern Morocco. Preliminary report, age and palaeobiogeographical implications. Geological Magazine, 147(6), 860-870

Adnet S. et al. (2009): New fossil teeth of the White Shark (Carcharodon carcharias) from the Early Pliocene of Spain. Implication for its paleoecology in the Mediterranean. Neues Jarbrbuch für Geologie und Paläontologie, 55:197-204.

Adnet, S. et al (2009): Review of the enigmatic Eocene shark genus Xiphodolamia (Chondrichthyes, Lamniformes) with description of a new species recovered from Angola, Iran and Jordan. Journal of African Earth Sciences, 55: 197-204.

Adnet, S. & Cappetta, H. (2008): New fossil triakid sharks from the early Eocene of Prémontré, France, and comments on fossil record of the family. Acta Palaeontologica Polonica, 53(3):433-448.

Adnet. S. et al. (2008): Contribution of Eocene sharks and rays from southern France to the history of deep-sea selachians. Acta Geologica Polonica, 58 (2): 261-264

Adnet, S. et al. (2008): Re-evaluation of squaloid sharks from the Albian and Cenomanian of Lithuania. Cretaceous Research. 29: 711-722